# image-tools

Judges, signs and verifies the container images of [netOrk](https://git.netork.io/NetOrk/netork).
Every image repository of NetOrk uses these tools at a pinned commit, so the same rules apply
to every link of the chain:

```
netork/base-os ──► netork/base-python ──► netork/engine, netork/satellite
               └─► netork/ui
               └─► postgres, valkey, signal-api, apt-cacher-ng, unbound
```

Each link checks the signature of the image it builds on, is judged against CIS, and is signed
with its CIS result and SBOM attached (NetOrk/netork#1390).

## What it does

| | |
|---|---|
| **CIS gate** (`image_tools/cis.py`) | CIS Docker Benchmark 1.6.0 §4 and the CIS Debian Linux 12 controls that make sense in a container. Trivy measures what it automates; `image_tools/cis_os.sh` measures from inside the image. The image's repository decides the rest in its `cis.toml` and names the packages it may hold in `packages.allow`. |
| **SBOM** (`image_tools/sbom.py`) | The image's CycloneDX SBOM, as Trivy reads it. |
| **Signature** (`bin/sign.sh`) | A cosign signature on the reference and on every platform image behind it, with the CIS result and the SBOM as in-toto attestations. Nothing goes to a public transparency log. |
| **Verification** (`bin/verify-base.sh`, `bin/verify-signature.sh`) | Every `FROM` image of a Dockerfile is pinned by digest and signed with the key in `cosign.pub`. |
| **Verdict** (`image_tools/verify.py`) | Whether a rebuild improves on the pinned image, by netOrk's matcher (kb-server), for a base's nightly. |
| **Bump** (`image_tools/bump.py`) | One pull request in every repository of a `dependents.toml` that moves only the pin, and that repository's workflow started. |

## Using it in a workflow

```yaml
- name: Verify the base images
  uses: https://git.netork.io/NetOrk/image-tools/actions/verify-base@<commit>
  with:
    dockerfiles: docker/engine/Dockerfile

# build the image, then:
- name: Judge it
  uses: https://git.netork.io/NetOrk/image-tools/actions/judge@<commit>
  with:
    image: registry.netork.io/netork/engine:main-abc1234
    arch: amd64

# a base's nightly, to decide whether its pin moves:
- name: Judge it against the pin
  id: verdict
  uses: https://git.netork.io/NetOrk/image-tools/actions/verdict@<commit>
  env:
    NETORK_LICENSE_KEY: ${{ secrets.NETORK_LICENSE_KEY }}
  with:
    current: registry.netork.io/netork/base-os:pinned
    candidate: registry.netork.io/netork/base-os:13-20261022.3-amd64

# push it, then:
- name: Sign it
  uses: https://git.netork.io/NetOrk/image-tools/actions/sign@<commit>
  env:
    COSIGN_PRIVATE_KEY_B64: ${{ secrets.COSIGN_PRIVATE_KEY_B64 }}
    COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}
  with:
    ref: registry.netork.io/netork/engine@sha256:…
```

The judge action reads `cis.toml` and `packages.allow` from the working directory by default.
The runner needs Docker, Python 3.11 or newer, and `curl`; cosign is installed by the actions,
pinned and checked against its release checksum (`bin/install-cosign.sh`).

## Verifying an image yourself

```bash
cosign verify --key cosign.pub --insecure-ignore-tlog registry.netork.io/netork/base-os@sha256:…
cosign verify-attestation --key cosign.pub --insecure-ignore-tlog \
  --type https://netork.io/attestations/cis/v1 registry.netork.io/netork/base-os@sha256:…
```

`cosign.pub` is the public half of the `COSIGN_PRIVATE_KEY_B64` organization secret. The private
key comes base64 in one line: the runner masks a secret only where it appears whole.

## Development

```bash
pip install pytest ruff pyyaml shellcheck-py
pytest -q
ruff format --check . && ruff check .
shellcheck bin/*.sh image_tools/cis_os.sh
```

## License

MIT, see [LICENSE](LICENSE).